# -*- coding: utf-8 -*-
"""
@author:  yinbing.li(yinbing.li@zillnk.com)
@version: 1.0.0
@file:    leetcode278_第一个错误的版本.py
@time:    2023/3/8 13:05
"""


# The isBadVersion API is already defined for you.
# def isBadVersion(version: int) -> bool:

class Solution:
    def firstBadVersion(self, n: int) -> int:
        left = 1
        right = n
        while left < right:
            mid = (left + right) // 2
            if isBadVersion(mid):
                right = mid
            else:
                left = mid + 1
        return left
